Energy storage capsule and ship coating

Abstract

The invention provides an energy storage capsule and a ship coating, the energy storage capsule comprises a phase change layer and a shell layer, the phase change layer comprises a phase change material and an antifouling agent, the surface of the phase change layer is coated with the shell layer, and the shell layer comprises a polymer material. Wherein the phase change layer is the core part of the energy storage capsule, is usually made of a phase change material with high specific heat, and can absorb or release a large amount of heat when the temperature changes, so that the storage and release of energy are realized. The shell layer of the polymer material wraps the phase change layer, so that the external environment can be isolated, seawater corrosion is inhibited, the risk that the phase change material of the internal phase change layer is polluted or leaked is reduced, and the energy storage performance of the energy storage capsule is stable. Furthermore, according to the energy storage capsule provided by the invention, an anti-fouling agent is added into the phase change layer, and the anti-fouling agent can penetrate through the polymer material to be slowly released into external seawater in a seawater environment, so that biological adhesion and pollutant deposition in the seawater can be reduced, and the stability and long service life of the phase change material are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to an energy storage capsule and a ship coating. Background Art

[0002] Phase change energy storage is a new type of energy storage technology that uses phase change materials as energy storage materials. The large amount of energy released during the transformation of phase change materials can be used as energy storage, and only a small amount of energy is needed to melt the energy storage material into a phase change liquid, which can achieve high-efficiency and sustainable energy storage. However, traditional phase change materials often face some challenges during application. In some specific environments, phase change energy storage systems may be affected by pollution or corrosion. For example, pollutants such as dust and grease will adhere to their surface, thereby reducing the performance and reliability of the system. Phase change microcapsules are a material with phase change latent heat storage, and have certain application prospects in thermal management. By encapsulating the phase change material in the form of capsules, it can effectively deal with the common problem of pollutant adhesion and infiltration.

[0003] Furthermore, with the development of phase change energy storage technology, researchers have found that using seawater temperature differences for energy conversion is an environmentally friendly and renewable way of utilizing energy. In ocean thermal energy utilization systems, phase change energy storage technology can be used to store and balance energy. However, its application in marine environments is a special challenge for phase change energy storage systems. Salt, microorganisms, algae and other pollutants in seawater may adhere to the surface of the phase change energy storage system, resulting in performance degradation, increased corrosion, and even system failure. Summary of the invention

[0004] In view of the above problems, the present invention provides an energy storage capsule and a ship coating that can stably perform phase change energy storage functions in a seawater environment.

[0005] The first aspect of the present invention provides an energy storage capsule, which includes: a phase change layer and a shell layer, wherein the phase change layer includes a phase change material and an antifouling agent, and the shell layer is coated on the surface of the phase change layer, and the shell layer includes a polymer material.

[0006] According to the technical solution of the present invention, first, the phase change layer is the core part of the energy storage capsule. Usually, a phase change material with high specific heat is selected, such as heat storage wax, brine mixture, etc., which can absorb or release a large amount of heat when the temperature changes, so as to realize the storage and release of energy. In addition, by coating the phase change layer with a shell layer of polymer material, the external environment can be isolated, seawater corrosion can be inhibited, and the risk of contamination or leakage of the phase change material in the internal phase change layer can be reduced, so that the energy storage performance of the energy storage capsule is stable. Furthermore, the energy storage capsule provided by the present application also adds an antifouling agent to the phase change layer. In the seawater environment, the antifouling agent can be slowly released into the external seawater through the polymer material, thereby reducing the biological attachment and pollutant deposition in the seawater, and ensuring the stability and long life of the phase change material.

[0007] As a preferred technical solution, the phase change layer further includes: a heat conductive material, and the phase change layer is prepared by uniformly mixing the phase change material, the antifouling agent and the heat conductive material.

[0008] According to the preferred technical solution, the thermal conductive material can promote the conduction and uniform distribution of heat, which helps to improve the efficiency of energy storage and release. The phase change layer prepared by uniformly mixing the phase change material, the antifouling agent and the thermal conductive material can improve both the thermal conductivity and antifouling properties of the phase change energy storage capsule.

[0009] As a preferred technical solution, the thermally conductive material is modified graphene powder.

[0010] According to the preferred technical solution, graphene with high thermal conductivity and high impermeability is introduced into the phase change microcapsule. The layer structure of graphene as a two-dimensional carbon-based material is more conducive to phonon vibration and heat transfer, and has a lower surface thermal resistance. This stable lattice structure provides graphene with excellent thermal conductivity, thereby promoting the conduction and uniformity of heat inside the energy storage capsule, and helping to improve the efficiency of energy storage and release.

[0011] As a preferred technical solution, the modified graphene powder is formed by compounding graphene powder and sodium styrene sulfonate.

[0012] According to the preferred technical solution, firstly, sodium styrene sulfonate is a surfactant, which can form an electrostatic repulsive force between graphene sheets to prevent the graphene sheets from restacking, thereby significantly improving the dispersibility of graphene in a solvent or a polymer matrix.

[0013] Secondly, the composite of graphene and sodium styrene sulfonate can improve the processing performance of graphene in various matrices, making graphene easier to mix with other materials. In addition, the modified graphene is more stable in the mixed solution and is not easy to precipitate, which is very beneficial for long-term storage or transportation.

[0014] Finally, sodium styrene sulfonate can act as a bridge to promote the interfacial interaction between graphene and polymer materials such as phase change materials, thereby improving the mechanical properties and functional performance of energy storage capsules.

[0015] As a preferred technical solution, the phase change material is paraffin.

[0016] According to the preferred technical solution, paraffin wax has good chemical stability and high latent heat value, and can improve the energy storage performance and stability of phase change microcapsules.

[0017] As a preferred technical solution, the polymer material is melamine resin.

[0018] According to the preferred technical solution, the melamine resin has the properties of high temperature resistance and corrosion resistance, which can ensure the stability of the energy storage capsule in different environments and prevent internal material leakage.

[0019] As a preferred technical solution, the antifouling agent is cuprous oxide.

[0020] According to the preferred technical solution, cuprous oxide slowly releases copper ions (Cu+), which are toxic to many marine organisms. They can kill or inhibit the growth of algae, barnacles, shellfish and other organisms that may attach to the hull, thereby preventing the hull from being fouled by these organisms. For the energy storage capsule prepared by the present invention, cuprous oxide can slowly release copper ions through melamine resin, and the release rate of copper ions can be controlled by controlling the ratio of cuprous oxide to melamine resin, thereby ensuring a long-term antifouling effect.

[0021] As a preferred technical solution, in the phase change layer, the mass ratio of paraffin wax to graphene is 1:10; the mass ratio of paraffin wax to cuprous oxide is 1:1.

[0022] According to the preferred technical solution, the doping ratios of paraffin and graphene, paraffin and cuprous oxide are controlled within the above ranges, so that the phase change layer can have better energy storage performance while also having better thermal conductivity and anti-fouling properties.

[0023] A second aspect of the present invention provides a ship coating, which has the energy storage capsule provided in any one of the above technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the change of temperature of the energy storage capsule with the illumination time provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In this embodiment, an energy storage capsule is provided, which includes: a phase change layer and a shell layer, wherein the phase change layer includes a phase change material and an antifouling agent, and the shell layer is coated on the surface of the phase change layer, and the shell layer includes a polymer material.

[0027] The phase change layer is the core part of the energy storage capsule, and phase change materials with high specific heat are usually selected. The phase change material in the phase change layer can be any material with high specific heat, such as one or more combinations of thermal storage wax, brine mixture, molten salt, etc., without limitation. These phase change materials can absorb or release a large amount of heat when the temperature changes, thereby realizing energy storage and release.

[0028] The shell layer is coated on the surface of the phase change layer to isolate the internal phase change layer from the external environment. Therefore, for the marine environment, the shell layer needs to have a certain corrosion resistance, so as to reduce the risk of contamination or leakage of the phase change material of the internal phase change layer, so that the energy storage performance of the energy storage capsule is stable. Therefore, in this embodiment, a polymer material with good corrosion resistance is selected as the shell material.

[0029] In particular, in the energy storage capsule provided in this embodiment, an antifouling agent is also added to the phase change layer, wherein the antifouling agent can be selected from any substance that can play an antifouling role in a seawater environment. In a seawater environment, the antifouling agent can be slowly released into the external seawater through the polymer material, thereby reducing biological attachment and pollutant deposition in the seawater, and ensuring the stability and long life of the phase change material.

[0030] In some preferred embodiments, the phase change layer also includes: a thermally conductive material, and the phase change layer is prepared by uniformly mixing the phase change material, the antifouling agent and the thermally conductive material. The thermally conductive material can promote the conduction and uniform distribution of heat, which helps to improve the efficiency of energy storage and release. Among them, preferably, the thermally conductive material can be any material with excellent thermal conductivity, which is not limited here. Preferably, modified graphene powder is selected, and graphene with high thermal conductivity and high impermeability is introduced into the phase change microcapsule. The layer structure of graphene as a two-dimensional carbon-based material is more conducive to phonon vibration and heat transfer, and has a lower surface thermal resistance. This stable lattice structure provides excellent thermal conductivity for graphene, so it can promote the conduction and uniformity of heat inside the energy storage capsule, which helps to improve the efficiency of energy storage and release.

[0031] In this embodiment, when the capsule is placed in seawater, the phase change material in the capsule changes from solid to liquid according to the temperature change of the surrounding seawater. When the seawater temperature rises, the phase change material in the capsule absorbs heat and changes from solid to liquid, storing energy. When the seawater temperature drops, the phase change material releases the stored heat and changes from liquid to solid, thereby releasing energy. By connecting the capsule to a generator or other energy conversion device, the stored energy can be converted into electrical energy or other forms of usable energy. Antifouling agents are released on the hull of the ship to reduce the attachment of marine organisms and the deposition of pollutants. The phase change layer prepared by uniformly mixing the phase change material, antifouling agent and thermal conductive material can take into account the improvement of the thermal conductivity and antifouling properties of the phase change energy storage capsule.

[0032] Wherein, preferably, the modified graphene powder is formed by compounding graphene powder and sodium styrene sulfonate.

[0033] In this embodiment, firstly, sodium styrene sulfonate is a surfactant, which can form an electrostatic repulsive force between graphene sheets to prevent the graphene sheets from restacking, thereby significantly improving the dispersibility of graphene in a solvent or a polymer matrix.

[0034] Secondly, the composite of graphene and sodium styrene sulfonate can improve the processing performance of graphene in various matrices, making graphene easier to mix with other materials. In addition, the modified graphene is more stable in the mixed solution and is not easy to precipitate, which is very beneficial for long-term storage or transportation.

[0035] Finally, sodium styrene sulfonate can act as a bridge to promote the interfacial interaction between graphene and polymer materials such as phase change materials, thereby improving the mechanical properties and functional performance of energy storage capsules.

[0036] Preferably, the phase change material is paraffin wax, which has good chemical stability and high latent heat value, and can improve the energy storage performance and stability of the phase change microcapsules.

[0037] Preferably, the polymer material is melamine resin, which has high temperature resistance and corrosion resistance, can ensure the stability of the energy storage capsule in different environments, and prevent internal material leakage.

[0038] Among them, preferably, the antifouling agent is cuprous oxide. Cuprous oxide slowly releases copper ions (Cu+), which are toxic to many marine organisms. They can kill or inhibit the growth of algae, barnacles, shellfish and other organisms that may attach to the hull, thereby preventing the hull from being fouled by these organisms. For the energy storage capsule prepared by the present invention, cuprous oxide can slowly release copper ions through melamine resin, and the release rate of copper ions can be controlled by controlling the ratio of cuprous oxide and melamine resin, thereby ensuring a long-term antifouling effect.

[0039] Further preferably, since the phase change layer contains phase change material, thermal conductive material and antifouling agent at the same time, in order to ensure the energy storage density of the phase change layer while taking into account the thermal conductive and antifouling effects, in the phase change layer, the mass doping ratio of paraffin wax to graphene can be selected as 1:10; the mass doping ratio of paraffin wax to cuprous oxide can be selected as 1:1. Controlling the doping ratio of paraffin wax to graphene, paraffin wax to cuprous oxide within the above range can make the phase change layer have better energy storage performance, while also taking into account better thermal conductive and antifouling performance.

[0040] The following experiment further demonstrates the performance of the energy storage capsule provided by this embodiment.

[0041] 1. Material Preparation

[0042] 1.1 Preparation of phase change emulsion

[0043] (1) Preparation of modified graphene

[0044] First, 100 mg of graphene and 200 mg of sodium styrene sulfonate (PSS) were added to 200 mL of deionized water, dissolved under magnetic stirring, and then dispersed by ultrasound for 10 h. Next, the mixture was refluxed at 80 ° C for 12 hours. The suspension was then filtered and washed several times until the unreacted sodium styrene sulfonate (PSS) was removed. Finally, they were dried at 80 ° C for 6 hours to obtain modified graphene.

[0045] (2) Preparation of phase change emulsion

[0046] The modified graphene powder was dispersed in water and ultrasonically treated at a power of 300 W for 1 hour to form a graphene aqueous suspension. Paraffin (7 g), 7 mL of graphene aqueous suspension, and cuprous oxide solution were added to deionized water, and then stirred and emulsified at 75 ° C at a stirring speed of 19000 rpm for 5 minutes. The pH of the mixed solution was adjusted to about 4 with a saturated citric acid solution to prepare a phase change emulsion.

[0047] 1.2 Preparation of shell materials

[0048] (1) Preparation of melamine-formaldehyde (MF) prepolymer

[0049] First, formaldehyde solution (2.8 g) and melamine (1.5 g) were mixed with 10 mL of deionized water. After that, the mixture was stirred at 75° C. (500 rpm), and the pH of the mixture was adjusted to 9 with a 10 wt % triethanolamine solution. The mixture was stirred for 1 hour until it became transparent, and a melamine-formaldehyde (MF) prepolymer was prepared.

[0050] (2) Preparation of energy storage capsules

[0051] Melamine-formaldehyde (MF) prepolymer was dripped into the emulsion within 15 minutes, while the emulsion was stirred (400 rpm) in a water bath at 80°C. After all the melamine-formaldehyde (MF) prepolymer was added, it was stirred continuously for 2.5 hours. The pH of the mixed emulsion was adjusted to 9 with triethanolamine to terminate the polymerization reaction. The energy storage capsule was obtained by filtration, and the energy storage capsule was applied to the surface of the object, washed with deionized water at room temperature until impurities were removed, and then dried in an oven at 40°C for 24 hours to obtain a sample with an energy storage capsule coating.

[0052] 2 Material characterization

[0053] 2.1 Photothermal conversion performance

[0054] A xenon lamp was used as a simulated sunlight system, and the prepared energy storage capsules were placed under one sun. After a period of irradiation, the light source was turned off, and an infrared thermal imager was used to record the temperature changes on the surface of the composite material during the whole process.

[0055] The energy storage capsule prepared by the present invention has a high photothermal energy conversion and storage capacity. When there is light, the energy storage capsule can absorb light and convert it into heat energy and store it in the phase change energy storage filler, thereby increasing the temperature of the composite material surface. Figure 1 As shown in the figure, with the increase of irradiation time, the temperature of all energy storage capsule coating samples increases. When the temperature reaches about 42°C, the temperature rise rate slows down due to the phase change of the phase change material in the phase change layer. After a period of time, the highest temperature reaches 72.42°C. When the light is lost, as the ambient temperature decreases, the surface temperature of the composite material begins to decrease. When the temperature drops to the phase change temperature, the phase change material in the phase change layer releases latent heat by phase change conversion to maintain the constant temperature of the energy storage capsule and no longer continues to decrease. Therefore, a constant temperature platform of about 10 minutes appears in the temperature change trend diagram. After that, all energy storage capsule samples naturally cool to room temperature.

[0056] 2.2 Anti-bacterial adhesion test

[0057] (1) The prepared energy storage capsule coating sample was placed in a phosphate buffer solution (PBS) and soaked for 24 hours, then taken out and irradiated with an ultraviolet lamp (20 W, 253.7 nm) for 30 minutes.

[0058] (2) Place the energy storage capsule coating sample in a culture dish that has also been irradiated with ultraviolet light, add 10 mL of Luria-Bertani (LB) liquid culture medium and a certain concentration of bacterial solution (108 CFU / mL). Then seal the surface dish with a sealing film with a breathing hole and place it in a biochemical incubator for 12 hours (48 hours for marine bacteria) at a temperature of 37°C. When the cultured bacteria are marine bacteria, the temperature is 25°C.

[0059] (3) After the incubation, take out the sample, rinse the coating surface with 10 mL of LB medium, and then dilute to 0.1% of the original concentration. Then take 10 μL of the diluted bacterial solution and evenly spread it on the solid culture medium, and place it in a biochemical incubator at 37°C (25°C for marine bacteria) for 24 hours.

[0060] The samples were stained with the LIVE / DEAD BacLight bacterial activity kit, and the bacterial cells adhered to the coating surface were observed using a fluorescence microscope (Scope A1, Zeiss). The relative adsorption of bacteria was analyzed using ImageJ software.

[0061] On the surface of the silicon slide of the blank sample, many green fluorescent spots were observed, indicating that a large number of marine bacteria adhered to the surface. However, after observation, almost no bacteria adhered to the surface of the marine antifouling coating prepared in this embodiment, which can prove that the marine antifouling coating prepared in this embodiment can slowly release the antifouling agent for a long time, thereby effectively preventing marine bacteria from entering the surface.

[0062] In some other embodiments, a ship coating is provided, which has the energy storage capsule provided in any of the above technical solutions. The cuprous oxide antifouling agent in the energy storage capsule can be slowly released through the shell layer, so that the antifouling agent can be released on the surface of the ship hull to reduce the attachment of marine organisms and the deposition of pollutants.

[0063] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy storage capsule, characterized in that: include: A phase change layer, the phase change layer comprising a phase change material and an antifouling agent; The shell layer is coated on the surface of the phase change layer, and the shell layer includes a polymer material.

2. The energy storage capsule according to claim 1, characterized in that: The phase change layer further comprises: The phase change layer is prepared by uniformly mixing the phase change material, the antifouling agent and the heat conductive material.

3. The energy storage capsule according to claim 2, characterized in that: The thermal conductive material is modified graphene powder.

4. The energy storage capsule according to claim 3, characterized in that: The modified graphene powder is formed by compounding the graphene powder with sodium styrene sulfonate.

5. The energy storage capsule according to claim 1, characterized in that: The phase change material is paraffin.

6. The energy storage capsule according to claim 1, characterized in that: The polymer material is melamine resin.

7. The energy storage capsule according to claim 1, characterized in that: The antifouling agent is cuprous oxide.

8. The energy storage capsule according to claim 3, characterized in that: In the phase change layer, the mass doping ratio of the paraffin wax to the graphene is 1:10; the mass doping ratio of the paraffin wax to the cuprous oxide is 1:

1.

9. A ship coating, characterized in that: The ship coating has the energy storage capsule according to any one of claims 1-8.

Images